Your first post made me think you were going to record orchestras, then we settled on sampled orchestras. Albion, and the other Spitfire things I have runs on a number of platforms, and the playability of the sounds is really down to your manipulation. I doubt that there is a 'best' - and any of the popular heavyweight platforms will work for you, if you put the effort in. The trouble with MIDI is it's edit heavy. For orchestral work, the killer thing is being able to edit pitchbend, aftertouch, controllers, and then note by note editing - so you need to shift notes in time, pitch and of course velocity. How exactly these things get done, in Cubase which I'm happy with, are by different types of edit screens. I currently use the normal old fashioned key based screen most, followed by the list editor, then the score editor and occasionally the drum editor. Others will be quite different. Cubase does these thing pretty well I think. I can work quickly and pretty effectively. you need to have some dexterity with the mouse, but it works. after all these years I'm still not quite fluid with drawing in curves - to do expression as a second pass usually means pressing record and using the fader on my keyboard. This and things like pitchbend can be draw in with the mouse, but I cannot work the mouse the way I can with a real knob or wheel. I bet Protools now can do this kind of stuff as well - I don't know, because when I started with Cubase seriously for work, protools was a leader in audio recording, but very weak in MIDI. I don't know it's status now. I'd hope its now good. Other can comment probably.